Trees might not be able to store as much carbon as we thought, new study suggests

Researchers at Western Sydney University (WSU) in Australia have found that "common" Australian trees do not store as much carbon as had been previously assumed, a discovery that could have big implications on how we tackle climate change.

According to a news release from the university, the study, published in the journal Nature Climate Change, found that Eucalyptus forests may require extra soil nutrients to grow and "take advantage" of additional carbon dioxide (CO2) in the atmosphere.

Large areas of "remnant native eucalypt forest" were exposed to heightened levels of CO2 at a WSU facility. Researchers found that while the extra CO2 increased levels of photosynthesis, it did not result in increases in leaves, stems and wood.

WSU said that this was in contrast to research conducted in the U.S. and Europe. Teams there had added extra CO2 to areas of temperate forests, and trees' growth had increased by roughly 23 percent.

The results could be significant when it comes to climate change models.

"The world pays a lot of attention to climate change modelling, including predictions on the amount of carbon that will be stored in trees," David Ellsworth, from the university's Hawkesbury Institute for the Environment, said in a statement on Tuesday.

"These reports are based on models and data taken largely from temperate forests where nutrients are in adequate supply, meaning that estimates on carbon absorption do not account for nutrient shortages on forest productivity," Ellsworth added.

Ellsworth went on to state that his team's results indicated that global estimates of carbon storage in forests may be too high, "since many of the world's sub-tropical and tropical forested regions exist on low-nutrient soils."

"Many greenhouse crops such as tomatoes, cut flowers and cucumbers are given added CO2 to make them grow bigger, faster and yield more fruit," Ellsworth went on to explain.

In Australia's native forests, conditions for plants were not as ideal, he added.

"Australia's soils are very old and weathered by millions of years of sun and rain, meaning soils are very low in nutrients, and most of the available nutrients are tied up inside wood, leaves and roots."

"It means that our soils simply lack the available nutrients that would let trees take advantage of the extra CO2 they find in the air."